Monolithic integrated optoelectronic chip for vector force detection

Sensors with a small footprint and real-time detection capabilities are crucial in robotic surgery and smart wearable equipment.Reducing device footprint while maintaining its high performance is a major challenge and a significant limitation to their development.Here,we proposed a monolithic integrated micro-scale sensor,which can be used for vector force detection.This sensor combines an optical source,four photodetectors,and a hemispherical silicone elastomer component on the same sapphire-based AlGaInP wafer.The chip-scale optical coupling is achieved by employing the laser lift-off techniques and the flip-chip bonding to a processed sapphire substrate.This hemispherical structure device can detect normal and shear forces as low as 1mN within a measurement range of 0–220 mN for normal force and 0–15 mN for shear force.After packaging,the sensor is capable of detecting forces over a broader range,with measurement capabilities extending up to 10 N for normal forces and 0.2 N for shear forces.It has an accuracy of detecting a minimum normal force of 25 mN and a minimum shear force of 20 mN.Furthermore,this sensor has been validated to have a compact footprint of approximately 1.5 mm^(2),while maintaining high real-time response.We also demonstrate its promising potential by combining this sensor with fine surface texture perception in the fields of compact medical robot interaction and wearable devices.