The wireless hydrogel-based sensor developed by Chinese scientists is biodegradable and can be injected into the brain to measure temperature, pH, intracranial pressure and blood flow with the help of an external ultrasound probe 中國科學家開發的無線水凝膠感測器可生物降解，可注入大腦，借助外部超音波探頭測量溫度、pH、顱內壓和血流量.